simulate mouse click with VB 2005

Question

Hi, all I find are solutions for VB6, but they don't work in VB 2005 :( Here's what I want to do: I want to simulate a mouse click in the window of another application. Since this app might not be running in the foreground I want to send the click via SendMessage directly to that window. How does that work? What are the proper declarations and constants? A tested piece of code would be great! Another question in this context: I want to adress the position where the click happens as RELATIVE X/Y coordinates measured in pixels. This means that X=100, Y=200 would be 100 pixels to the right from the left border of this application's window frame and 200 pixels down from the top border. So no matter where the window is located on the screen I would always click on the same spot inside the window. Is there a transformation calculation needed (possibly involving the window's screen coordinates and the current screen resolution)? Thanks a lot in advance!!!